Prosthetic with voice coil valve

ABSTRACT

A prosthetic includes a pair of prosthetic members movably coupled together to allow movement of the pair of prosthetic members with respect to one another. A hydraulic actuator or damper including hydraulic fluid in a hydraulic chamber is coupled to one of the pair of prosthetic members. A hydraulic piston is movably disposed in the hydraulic chamber and coupled to another of the pair of prosthetic members. A hydraulic flow channel is fluidly coupled between opposite sides of the chamber to allow hydraulic fluid to move between the opposite sides of the chamber as the hydraulic piston moves therein. A voice coil valve is coupled to the hydraulic flow channel to vary resistance to flow of hydraulic fluid through the flow channel, and thus movement of the piston in the chamber, and thus influencing a rate of movement of the pair of prosthetic members with respect to one another.

PRIORITY CLAIM(S)

This is a continuation of U.S. patent application Ser. No. 13/829,714,filed Mar. 14, 2013, now U.S. Pat. No. 9,028,557, which is herebyincorporated herein by reference.

BACKGROUND Field of the Invention

The present invention relates generally to prosthetics with a hydraulicdamper or actuator. More particularly, the present invention relates toa prosthetic knee.

Related Art

The development of a prosthetic knee with a more natural function orgait is an ongoing endeavor. Examples of prosthetic knees include U.S.Pat. No. RE39,961 (U.S. Pat. No. 6,113,642) and U.S. Pat. No. 7,655,050;and the Plie® prosthetic knee by Freedom Innovations, Inc.

Prosthetic knees often incorporate a hydraulic damping scheme to limitor control movement about the knee. The hydraulic damping systems oftenutilize a solenoid valve to limit or resist the flow of hydraulic fluid.A solenoid valve is typically on or off, and can typically operate bydrawing a plunger into an activated magnetic coil and against a spring,which spring can return the plunger when the coil is deactivated. Inaddition, some hydraulic damping systems may also, or in thealternative, utilize a stepper motor.

Prior art prosthetic knees often do not meet the advanced demands neededby today's amputee.

SUMMARY OF THE INVENTION

It has been recognized by the inventors of the present invention thatprior art solenoid valves in hydraulic prosthetics lack an ability tofinely adjust rates of fluid flow; and that prior art stepper motorcontrol valves in hydraulic prosthetics lack response time to controlfluid in both directions, often resulting in parallel systems withdouble the weight and complexity. It has been recognized by theinventors of the present invention that it would be advantageous todevelop a prosthesis, and namely an above knee prosthesis or prostheticknee, and/or a hydraulic damper or actuator for such prosthesis, and/ora control valve for such a prosthesis or hydraulic system, that providesbi-directional positioning, proportional control, rapid response and/orlow power consumption. In addition, it has been recognized by theinventors of the present invention that it would be advantageous todevelop a prosthesis, and namely an above knee prosthesis or prostheticknee, and/or a hydraulic damper or actuator for such prosthesis, and/ora control valve for such a prosthesis or hydraulic system, that providestwo different regions of linear proportional control.

In addition, it has been recognized by the inventors of the presentinvention that it would be advantageous to incorporate a voice coilvalve, rather than a solenoid valve, into a prosthetic knee, and toaddress the prior size concerns that such a voice coil valve may raise.Furthermore, it has been recognized by the inventors of the presentinvention that a voice coil valve can provide reciprocal orbidirectional movement based on the polarity of an applied current (asopposed to the unidirectionally driven movement in that the armature ofa solenoid that only moves in one direction regardless of the polarityof the current applied, and that requires a spring for return movement).The inventors further recognized that the force produced by the voicecoil actuator is proportional (and substantially linear) to the currentapplied (and the velocity of the coil is proportional to the voltageapplied), unlike a solenoid (with non-linear time and force response,and higher power consumption towards one end of the stroke due to theneed of constantly working against the return spring force). Thus, theactuator has a substantially linear time and force response. Themovement and force of the voice coil motor is based on the Lorentz Forceprinciple and equation, unlike a spring returned solenoid.

The invention provides a prosthetic with a pair of prosthetic membersmovably coupled together to allow movement of the pair of prostheticmembers with respect to one another. In one aspect, the prosthetic canbe a prosthetic knee. A hydraulic actuator or damper includes hydraulicfluid in a hydraulic chamber coupled to one of the pair of prostheticmembers, and a hydraulic piston movably disposed in the hydraulicchamber coupled to another of the pair of prosthetic members. Ahydraulic flow channel is fluidly coupled between opposite sides of thechamber to allow hydraulic fluid to move between the opposite sides ofthe chamber as the hydraulic piston moves therein. A voice coil valve iscoupled to the hydraulic flow channel to vary resistance to flow ofhydraulic fluid through the flow channel, and thus movement of thepiston in the chamber, and thus influencing a rate of movement of thepair of prosthetic members with respect to one another.

The voice coil valve can reciprocally and selectively position a valve,or spool thereof, in a bidirectional movement based on the polarity ofthe current applied to the voice coil. Thus, the valve can bebi-directionally driven in back and forth directions, andbi-directionally positioned. The amount of current can be selected andvaried to selectively position a coil with respect to a magnet. Thepolarity of the current can be selected and changed to select and changethe direction of travel of the valve or spool. The force produced by thevoice coil valve is proportional (and substantially linear) to thecurrent applied (and the velocity of the coil is proportional to thevoltage applied), unlike a solenoid (with non-linear time and forceresponse). Thus, the voice coil valve has a substantially linear timeand force response. The movement and force of the voice coil is based onthe Lorentz Force principle and equation, unlike a solenoid. Inaddition, the direction of movement of the coil can be selected, drivenand varied by selecting and varying the polarity of the current, unlikea solenoid (which has the same direction of travel irrespective ofpolarity; i.e. changing the polarity of a solenoid does not alter thedirection of induced motion). Thus, the direction of travel of the coilis based on the polarity of the current. The voice coil valve has arapid response rate (i.e. greater than 100 cycles per second), and a lowpower consumption (i.e. less than 1.8 Watts, or 150 mAmps @ 12V), unlikea solenoid.

In addition, the invention provides a prosthetic with a pair ofprosthetic members movably coupled together to allow movement of thepair of prosthetic members with respect to one another. A hydraulicactuator or damper includes hydraulic fluid in a hydraulic chambercoupled to one of the pair of prosthetic members, and a hydraulic pistonmovably disposed in the hydraulic chamber and coupled to another of thepair of prosthetic members. The hydraulic piston divides the chamberinto opposite sides. A hydraulic flow channel is fluidly coupled betweenthe opposite sides of the chamber to allow hydraulic fluid to movebetween the opposite sides of the chamber as the hydraulic piston movestherein. A hydraulic valve is operatively coupled in the hydraulic flowchannel and includes an orifice and a spool movable with respect to oneanother to selectively resist flow of the hydraulic fluid through theorifice. The prosthetic includes an electric actuator to move theorifice and the spool with respect to one another. The actuator includesa permanent magnet and a coil movable with respect to one another, andreciprocally positionable with current polarity induced, bi-directionalmovement, by selectively changing a polarity of electric current appliedto the electric actuator, such that the spool is selectively positionedand bi-directionally driven in back and forth directions, such that thehydraulic valve varies resistance to the flow of hydraulic fluid throughthe flow channel. The actuator has a substantially linear time and forceresponse with a rapid response rate, capable of greater than 100 cyclesper second, and a low power consumption less than 1.8 Watts. The valvehas a pair of different, substantially linear control regions including:a first region providing a region of control during slowextension/retraction of the hydraulic actuator or damper between 1.5 to2.5 inches per second, and a second region providing a region of controlduring fast extension/retraction of the hydraulic actuator or damperbetween 6 to 8 inches per second.

Furthermore, the invention provides a prosthetic knee for an above kneeamputee with pair of prosthetic members including a thigh linkconfigured to be coupled to a remnant limb of the amputee, and pivotallycoupled to a shank link configured to be coupled to an artificial foot.The thigh link and shank link are pivotally coupled together at aprimary pivot to allow flexion and extension of the shank link withrespect to the thigh link. A hydraulic actuator or damper includeshydraulic fluid in a hydraulic chamber coupled to one of the pair ofprosthetic members, and a hydraulic piston movably disposed in thehydraulic chamber and coupled to another of the pair of prostheticmembers. The hydraulic piston divides the chamber into opposite sides. Ahydraulic flow channel is fluidly coupled between the opposite sides ofthe chamber to allow hydraulic fluid to move between the opposite sidesof the chamber as the hydraulic piston moves therein. A voice coil valveis coupled to the hydraulic flow channel to vary resistance to flow ofhydraulic fluid through the flow channel, and thus movement of thepiston in the chamber, and thus pivoting of the pair of prostheticmembers with respect to one another. The voice coil valve includes: anorifice and a spool movable with respect to one another to selectivelyresist flow of the hydraulic fluid through the orifice; and a permanentmagnet and a coil, coupled to the valve to move the orifice and thespool with respect to one another, and movable with respect to oneanother, and reciprocally positionable with current polarity induced,bi-directional movement, by selectively changing a polarity of electriccurrent applied to the electric actuator, such that the spool isselectively positioned and bi-directionally driven in back and forthdirections, such that the hydraulic valve selectively varies resistanceto the flow of hydraulic fluid through the flow channel. The voice coilvalve has a rapid response rate, capable of greater than 100 cycles persecond, and a low power consumption less than 1.8 Watts.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional features and advantages of the invention will be apparentfrom the detailed description which follows, taken in conjunction withthe accompanying drawings, which together illustrate, by way of example,features of the invention; and, wherein:

FIG. 1 is a perspective view of a prosthetic knee in accordance with anembodiment of the present invention;

FIG. 2 is a side view of the prosthetic knee of FIG. 1;

FIG. 3 is a cross-sectional side view of the prosthetic knee of FIG. 1,taken along line 3-3 in FIG. 1;

FIG. 4 is a cross-sectional side view of a hydraulic system of theprosthetic knee of FIG. 1;

FIG. 5a is a cross-sectional schematic view of the hydraulic system ofFIG. 4, shown in cylinder compression or knee flexion;

FIG. 5b is a cross-sectional schematic view of a control valve or voicecoil valve of FIG. 1 shown in cylinder compression or knee flexion;

FIG. 6a is a cross-sectional schematic view of the hydraulic system ofFIG. 4, shown in cylinder extension or knee extension;

FIG. 6b is a cross-sectional schematic view of the control valve orvoice coil valve of FIG. 1 shown in extension;

FIG. 7 is a partial cross-sectional side view of the prosthetic knee ofFIG. 1, taken along line 3-3 in FIG. 1;

FIG. 8 is a perspective view of another prosthetic knee in accordancewith another embodiment of the present invention showing a differentembodiment of a packaging solution for a control valve or voice coilvalve;

FIG. 9 is a side view of the prosthetic knee of FIG. 8;

FIG. 10 is a cross-sectional side view of the prosthetic knee of FIG. 8,taken along line 10-10 in FIG. 8;

FIG. 11 is a perspective view of another prosthetic knee in accordancewith another embodiment of the present invention;

FIG. 12 is a cross-sectional side view of the prosthetic knee of FIG.11, taken along line 12-12 in FIG. 11;

FIG. 13a is a cross-section side schematic view of a hydraulic actuatoror damper, or hydraulic system, of the prosthetic knee of FIG. 11, showin compression or flexion;

FIG. 13b is a schematic cross-sectional side view of a control valve orvoice coil valve of FIG. 11, shown in cylinder compression or kneeflexion;

FIG. 13c is a schematic cross-sectional side view of the control valveor voice coil valve of FIG. 11 with enhanced power off functionality,shown in cylinder compression or knee flexion and metering in anon-powered state;

FIG. 14a is a cross-section side schematic view of a hydraulic actuatoror damper, or hydraulic system, of the prosthetic knee of FIG. 11, showin cylinder extension and knee extension;

FIG. 14b is a schematic cross-sectional side view of the control valveor voice coil valve of FIG. 11, shown in cylinder extension and kneeextension;

FIG. 14c is a schematic cross-sectional side view of the control valveor voice coil valve of FIG. 11, shown in cylinder extension and kneeextension and in a non-powered state;

FIG. 15 is a perspective view of another prosthetic knee in accordancewith another embodiment of the present invention showing a rotary vanehydraulic system;

FIG. 16 is another perspective view of the prosthetic knee of FIG. 15;

FIG. 17 is a cross-sectional side view of the prosthetic knee of FIG.15, taken along line 17-17 in FIG. 15;

FIG. 18 is a partial cross-sectional perspective view of the prostheticknee of FIG. 15;

FIG. 19 is partial perspective view of a portion of a rotary vane typehydraulic actuator or damper of the prosthetic knee of FIG. 15, andnamely a central block forming a portion of a hydraulic chamber with arotary vane therein;

FIG. 20 is a partial perspective view of a portion of another rotaryvane type hydraulic actuator or damper in accordance with another aspectof the present invention, and namely a central block forming a portionof a hydraulic chamber with a rotary vane therein;

FIG. 21 is a cross-sectional side view of another hydraulic system ofthe prosthetic knee in accordance with another embodiment of the presentinvention employing the use of a twin wall cylinder, which arranges thefluid flow in dual concentric tubes, with one embodiment consisting ofan inner working chamber (inner wall) containing a piston, and an outerconcentric chamber (outer wall) providing the flow return circuit fromone side of the piston to the other;

FIG. 22 is a cross-sectional side view of another hydraulic system inaccordance with another embodiment of the present invention employing athrough rod cylinder (shown with the control valve or voice coil valveseparate from a housing thereof); and

FIG. 23 is a cross-sectional perspective view of the hydraulic system ofFIG. 22 (shown with the control valve or voice coil valve separate froma housing thereof).

In the above mentioned figures, hydraulic fluid has been removed forvisibility of the components. Although the hydraulic fluid is not shown,those skilled in the art will clearly understand the volumes itoccupies, and the channels it flows through.

Reference will now be made to the exemplary embodiments illustrated, andspecific language will be used herein to describe the same. It willnevertheless be understood that no limitation of the scope of theinvention is thereby intended.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENT(S)

The invention provides a prosthetic device for use by an amputee. Theprosthetic device is shown herein configured as a prosthetic knee foruse by an above-knee amputee. The prosthetic device of the presentinvention can be configured as other prosthetics and/or for use in otherlocations. For example, the prosthetic device can be configured for useas a prosthetic ankle for a below-knee amputee, or an above-kneeamputee.

The prosthetic device or prosthetic knee can have a pair of prostheticmembers that are movably and/or pivotally coupled to one another, andmove and/or pivot with respect to one another. For example, the pair ofprosthetic members can move in flexion and extension in the case of aprosthetic knee. In addition, the prosthetic members can move indorsiflexion and plantar-flexion in the case of a prosthetic ankle. Theprosthetic members can move and/or pivot about a single pivot joint oraxle, or across a locus of points such as in a multi-bar linkage, orother type of linkage.

A hydraulic actuator or damper can also be coupled to and between thepair of prosthetic members to control or limit the movement and/orpivoting between the members. The terms “hydraulic actuator”, “hydraulicdamper” and “hydraulic actuator or damper” are used interchangeablyherein to refer to a hydraulic system that imposes some type oflimitation or control on the movement of a hydraulic fluid, and thussome type of limitation or control on the relative movement between theprosthetic members. The hydraulic system can be a hydraulic damper thatsimply limits or resists movement of the hydraulic fluid, and thussimply limits or resists movement between the pair of prostheticmembers. The hydraulic system can be a hydraulic actuator that includesa hydraulic motor that drives or creates hydraulic pressure to drivemovement between the pair of prosthetic members. Such a hydraulicactuator can also be operated as a damper.

The hydraulic system can include a hydraulic separator, such as a pistonor vane, movable in a hydraulic chamber, such as a cylinder or rotarychamber, to displace hydraulic fluid from one side of the workingchamber to the other. The piston can be coupled to one of the prostheticmembers, while the chamber is coupled to the other of the prostheticmembers in the embodiment of a linear piston damper, or in theembodiment of a rotary piston damper. Such couplings can be secondarypivotal couplings, separate from a primary pivot between the pair ofmembers. The piston can divide the chamber into opposite sides and thehydraulic system can be configured to displace the fluid from one sideof the piston to the other, or from one side of the chamber to theother. Thus, the hydraulic system can have a hydraulic flow channelfluidly coupled between the opposite sides of the chamber to allow thehydraulic fluid to move between the opposite sides of the chamber as thepiston moves therein. In one aspect, the hydraulic system can include anoverflow reservoir to accommodate the different volumes of the oppositesides of the chamber due to the volume of piston rod coupled to thepiston. In another aspect, the hydraulic system can include a piston rodon both sides of the piston, which exits the working chamber on bothsides, commonly termed a “thru-rod” damper, so that the sum of thevolume on both sides of the chamber during the stroke remains constant.

A control valve can be coupled to the hydraulic flow channel to varyresistance to the hydraulic fluid flow or vary the flow rate. Prior artsolenoid valves have been used to vary flow. Solenoid valves typicallyhave a stationary iron core with a coil, and a movable iron armaturethat is moved when current is applied to the coil. Solenoid valves alsotypically rely on a spring for return movement when the current isremoved from the coil. Thus, solenoid valves often have an on-offoperation. Solenoid valves generate force proportional to the square ofthe current (and are thus non-linear). Solenoids are relativelyinexpensive. It has been recognized by the inventors, however, thatsolenoid valves are or can be limited by unidirectionally drivenmovement in that the armature only moves in one direction regardless ofthe polarity of the current applied, and that a spring is required forreturn movement. In addition, it has been recognized by the inventorsthat solenoid valves are or can be limited by requiring additionalcurrent to overcome the spring force of the spring, thus requiringgreater power consumption. In addition, it has been recognized by theinventors that solenoid valves are or can be limited by slower responsetimes and/or non-linear response time (and force).

The inventors have recognized that the control valve can include anelectric actuator, coupled to a hydraulic valve, to reciprocally andselectively position the valve, or spool thereof, in a bidirectionalmovement based on the polarity of the current applied to the actuator.Thus, the valve can be bi-directionally driven in back and forthdirections, and bi-directionally positioned. The electric actuatorincludes a permanent magnet and a coil movable with respect to oneanother. The permanent magnet can have a magnetic field in which thecoil moves when a current is applied to the coil. As well, the sameresponse can be generated when the magnet moves, and the coil remainsstationary, when electricity is used. The amount of current can beselected and varied to selectively position the coil with respect to themagnet. The polarity of the current can be selected and changed toselect and change the direction of travel of the coil with respect tothe magnet. The force produced by the actuator is proportional (andsubstantially linear) to the current applied (and the velocity of thecoil is proportional to the voltage applied), unlike a solenoid (withnon-linear time and force response). Thus, the actuator has asubstantially linear time and force response. The movement and force ofthe voice coil motor is based on the Lorentz Force principle andequation, unlike a solenoid. In addition, the direction of movement ofthe coil can be selected, driven and varied by selecting and varying thepolarity of the current, unlike a solenoid (which has the same directionof travel irrespective of polarity; i.e. changing the polarity of asolenoid does not alter the direction). Thus, the direction of travel ofthe coil is based on the polarity of the current. The actuator, and thusthe valve, has a rapid response rate (i.e. greater than 100 cycles persecond), and a low power consumption (i.e. less than 1.8 Watts, or 150mAmps @ 12V), unlike a solenoid. Such an actuator or valve can bereferred to as a voice coil or voice coil valve. The actuator is coupledto the hydraulic valve, which is operatively coupled in the hydraulicflow path. The valve includes an orifice and a spool movable withrespect to one another. The actuator is coupled to the valve to move theorifice and the spool with respect to one another to selectively resistflow of the hydraulic fluid through the orifice. In one aspect, theactuator can move the spool with respect to the orifice. Thus, thehydraulic valve selectively varies the resistance of the hydraulic valveto the flow of hydraulic fluid through the flow channel.

The control valve and electrical actuator thereof can be operativelycoupled, or electrically coupled or wirelessly coupled, to controlelectronics, such as a circuit board with a microprocessor, forming acomputer to control the control valve, and thus the hydraulic system orhydraulic actuator or damper. The computer can control the hydraulicvalve to vary the flow rate of the hydraulic fluid, and thus theresistance to bending, of the knee. The computer can vary thecompression and extension of the hydraulic system or hydraulic actuatoror damper during the gait cycle of a prosthetic knee; and thus controlthe compression and extension of the prosthetic knee during gait. Thecomputer and the control valve can vary the resistance and the flow rateof the compression and/or extension of the hydraulic system during bothcompression and extension of the prosthetic knee or members thereof.

As illustrated in FIGS. 1-7, a prosthetic device, namely a prostheticknee, indicated generally at 10, is shown in an example implementationin accordance with an embodiment of the invention. The prosthetic knee10 includes a pair of prosthetic members, namely an upper member orrotor or thigh link 14, and a lower member or frame or shank link 18,that are pivotally coupled together at a primary pivot 22. The upper andlower members 14 and 18, or components thereof, can be machined or castfrom metal, such as aluminum, and/or injection molded from plastic. Theprimary pivot 22 can include an axle and bearings. The upper member 14can be disposed at a location of a natural knee, while the lower member18 can extend along a length of a natural shin or lower leg. Bothmembers 14 and 18 can have connectors 26 at distal ends thereof, such aspyramid connectors as known in the art, for attachment to a socket 30and a prosthetic foot and/or ankle (not shown), respectively. The socketcan be attached to a remnant limb of the amputee. Such sockets,connectors, feet and ankles are known in the art. In use, the lowermember can move with respect to the upper member in flexion andextension. The lower member 18 can have an exterior frame or exoskeletonthat partially surrounds an interior between the lower connector and theprimary pivot, and that is open or partially open in a rearwarddirection, or has an open rear. The exoskeleton can carry a power supply(such as batteries), control electronics such as a circuit board with amicroprocessor, etc.

The prosthetic knee 10 also has a hydraulic system 40 that can include ahydraulic actuator or damper 50 and a control valve 60. The hydraulicsystem 40 is coupled between the upper and lower members 14 and 18. Thehydraulic actuator or damper 50 includes a hydraulic chamber, namely ahydraulic cylinder 54, pivotally coupled to the lower member 18, and apiston 58 with a piston rod 62 pivotally coupled to the upper member 14.The pivotal connections between the hydraulic actuator or damper and theupper and lower members form secondary pivots, separated from theprimary pivot. In another aspect, the coupling of the hydraulic actuatoror damper can be reversed, with the cylinder coupled to the upper memberand the piston rod coupled to the lower member (as shown in FIGS. 8-10).The piston 58 can be cylindrical and can slidably move within thecylinder 54. In addition, the piston 58 divides the cylinder 54 orchamber into opposite sides. The cylinder 54 can be formed by a cylinderdisposed between opposite caps 70 and 72, one of which is a lower cap 70that is pivotally coupled to the lower member 18 (with an axle andbearings), and the other of which is an upper cap 72 that has anaperture to slidably receive the piston rod 62. The piston rod 62 ispivotally coupled to the upper member 14 (with an axle and bearings).

In addition, the linear piston damper system (or piston 58 and cylinder54) can utilize tightly toleranced components which eliminate the needfor elastomeric seals to separate the sides of the hydraulic chamber. Byusing a “metal-on-metal” fit between the piston and cylinder, the sealdrag (or stiction) which would be transferred to the amputee as ajarring or disjointed feeling, can be entirely removed from the system,or greatly reduced. The precision that can be required to form ahydraulic working chamber capable of locking without weeping can requirea gap between the acting surfaces of the piston and cylinder on theorder of 0.005 mm (0.0002 in). Furthermore, the surface finish that canrequired to facilitate smooth actuation on both surfaces of the pistonand cylinder can be between 0.20 to 0.41 μm (8 to 16 μin) Ra finish.

Hydraulic fluid (not shown for clarity of the components) can fill thecylinder 54 or chamber, and can be displaced from one side of thecylinder 54 or chamber (or piston 58) to the other as the piston 58moves therein. A hydraulic flow channel 66 is fluidly coupled betweenthe opposite sides of the cylinder 54 or chamber (or piston 58) to allowthe hydraulic fluid to move or displace between the opposite sides ofthe cylinder 54 or chamber (or piston 58) as the piston 58 movestherein. One or more channels can be formed in the caps 70 and 72 toform a portion of the hydraulic flow channel 66. A tube 74 (FIG. 7) canbe fluidly coupled to and can extend between the caps 70 and 72 tointerconnect the channels in the caps, and also to form a portion of thehydraulic flow channel 66. The upper cap 72 can have a channel extendingfrom an upper chamber or upper portion of the cylinder 54, while thelower cap 70 can have a channel extending from a lower chamber or lowerportion of the cylinder 54. In addition, the tube 74 can couple thechannel from the lower cap 70 to the upper cap 72 or channel thereof.Thus, the upper cap 72 can form and can define a manifold with at leasta portion of the hydraulic flow channel 66 formed therein. Within theupper cap 72 or manifold, the hydraulic channel 66 can have a proximalportion 66 a and a distal portion 66 b (the proximal and distalpositions being relative to the control valve 60). A bore 76 can beformed in the upper cap 72 or manifold, and can extend through theproximal portion 66 a of the hydraulic channel 66 to the distal portion66 b. An annular flange or mount 78 can extend from the upper cap 72 ormanifold, and can circumscribe the bore 76, and can form a portion ofthe bore.

As indicated above, the prosthetic knee 10 and the hydraulic system 40include a control valve 60 coupled to the hydraulic flow channel 66 tovary resistance to flow of hydraulic fluid through the flow channel, andthus movement of the piston 58 in the chamber 54, and thus influence arate of movement of the pair of prosthetic members 18 and 18 withrespect to one another. As discussed above, the control valve 60includes a hydraulic valve 80 that directly contacts and acts upon thehydraulic fluid, and an actuator 90 that drives and controls thehydraulic valve 80. The hydraulic valve 80 and the actuator 90 can befixed together as a single, operable unit, i.e. the control valve 60,that can be coupled to and carried by the hydraulic system 40, and thehydraulic actuator or damper 50. Thus, the control valve 60 can beremoved and replaced as a single unit to facilitate repair or customapplications. The control valve 60 can have, and the hydraulic valve 80and the actuator 90 can share, a housing or cartridge 100 that can havea fitting 104, such as screw threads, that engage and attach the housing100 to the cap 72 or manifold, such as at the annular flange or mount78. The flange or mount 78 and/or bore 76 can include screw threads toreceive the fitting 104 of the housing. Thus, the upper cap 72 ormanifold receives and carries the control valve 60, and the hydraulicvalve 80 and the actuator 90. In addition, the control valve 60 iscoupled to the bore 76, and the portions 66 a and 66 b of the hydraulicchannel 66.

The hydraulic valve 80 of the control valve 60 is operatively coupled inthe hydraulic flow path or channel 66, and includes at least one orifice110 and a spool 114 movable with respect to one another to selectivelyresist flow of the hydraulic fluid through the orifice. The spool 114can be selectively positioned with respect to the orifice(s) 110 toselectively increase and decrease a cross-sectional area through whichthe hydraulic fluid can flow. The spool 114 can be or can include asliding tube 116, and can have a distal end or at least one distalopening 118 that is selectively positionable with respect to the orifice110. The distal opening 118 can be formed in a sidewall of the slidingtube 116, or the open end thereof, or can be the open end or annularedge thereof. The orifice(s) 110 can be formed in an inner tube 122circumscribing the sliding tube 116 or spool 114. The spool 114 orsliding tube 116 can slide within the inner tube 122. Thus, the spool114 or sliding tube 116 can be selectively positioned by the actuator toselectively position the orifice(s) 110 and opening(s) 118 with respectto one another, and selectively increase and decrease a cross-sectionalarea through which the hydraulic fluid can flow. An outer diameter ofthe sliding tube 116 can match an inner diameter of the inner tube 122so that the tubes seal with respect to one another. In another aspect, adistal end or annular edge of the sliding tube or spool can bepositioned with respect to the orifice. In another aspect, the spool orsliding tube can circumscribe the inner tube (as opposed to the innertube circumscribing the spool or sliding tube).

The inner tube 122 can be rigidly affixed to the housing 100, and canextend out of the housing and into the bore 76 of the upper cap 72 ormanifold, through the proximal portion 66 a of the channel 66 and to thedistal portion 66 b of the channel. In addition, the inner tube 122 candefine an inner flow channel. The housing 100 (or the fitting 104thereof) can form or can include an outer tube 126 circumscribing theinner tube 122 and spaced apart therefrom, and defining an outer annularflow channel circumscribing the inner flow channel. The inner and outertubes 122 and 126 are coupled to the hydraulic flow channel 66 in theupper cap 72 or manifold. The outer tube 126 extends into the bore 76 ofthe upper cap 72 or manifold and to the proximal portion 66 a of thechannel 66. Thus, the orifice(s) 110, and the opening(s) 118, aredisposed between the inner and outer flow channels. The inner tube 122and the outer tube 126 each have a distal end with the one extendingbeyond the other, namely the inner tube can extend beyond the outertube. Thus, the inner tube 122 can extend through the bore 76 to thedistal portion 66 b of the flow channel 66, while the outer tube 126 canextend into the bore 76 and to the proximal portion 66 a of the flowchannel 66.

As stated above, the electric actuator 90 is coupled to the hydraulicvalve 80 to move the orifice(s) 110 and the spool 114 or sliding tube116 with respect to one another. The actuator 90 includes a permanentmagnet 140 and a coil 144 (removed for clarity) movable with respect toone another. The magnet 140 can have an outer wall or cup with anannular shape or a cup shape with an inner post forming an annular spacebetween the outer wall and the inner post. The magnet 140 has or createsa magnetic field. The coil 144 can have an annular wall or cup sized tofit in the annular space of the magnet. The coil 144 can include wireswrapped or coiled around the wall or cup. Thus, the coil 144 can bemovably positioned in the magnetic field of the magnet 140. A currentcan be applied to the coil 144 to move the coil with respect to themagnet 140. As described above, the current applied to the coil 144 inthe magnetic field of the magnet 140 produces a force that is directlyproportional to the electric current applied. In addition, the coil 144,and thus the control valve 60, has a substantially linear time and forceresponse. Furthermore, the coil 144, and thus the spool 114 or slidingtube 116, is bi-directionally driven by the current, or polaritythereof. The electric current applied to the coil 144 causes the coil,and thus the spool 114 or sliding tube 116, to move in either a firstdirection or a second direction based on a polarity of the electriccurrent. Thus, the coil 144, spool 144 and sliding tube 166 arereciprocally positionable with current polarity induced, bi-directionalmovement, by selectively changing the polarity of the electric currentapplied to the electric actuator 90 or coil 144 thereof. Thus, the spool114 and sliding tube 116 can be selectively positioned andbi-directionally driven in back and forth directions, so that thehydraulic valve 80 selectively varies the resistance, or effectivesurface area or size of the opening between the orifice(s) 110 andopening(s) 118, of the hydraulic valve 80, via the position of the spool114 or sliding tube 166 with respect to the inner tube 122, to the flowof hydraulic fluid through the flow channel or orifice(s) 110 andopening(s) 118 thereof. The control valve 60 or actuator 90 can have arapid response rate, greater than 100 cycles per second, and a low powerconsumption, less than 1.8 Watts (i.e. or 150 mA @ 12V). Furthermore,the control valve 60, and the coil 144 thereof, can be selectively andproportionally positionable, proportional to an amount of the electriccurrent applied to coil or the control valve. Thus, a selective andvariable amount of electric current with variable polarity applied tothe coil or control valve selectively and proportionally varies theresistance of the control valve, or the hydraulic valve 80 thereof, tothe flow of hydraulic fluid through the flow channel. While the coil hasbeen described above as movable with respect to a permanent magnet, itis contemplated that such a configuration can be reversed, with themagnet coupled to the spool or sliding tube, and movable with respect tothe coil.

The control valve 60 can be characterized as a voice coil valve, and theactuator 90 can be characterized as a voice coil. Therefore, theprosthetic knee 10 and hydraulic system 40 thereof can utilize a voicecoil valve. As noted above, the control valve 60 or voice coil valvedescribed above provides bi-directional positioning, proportionalcontrol, rapid response and/or low power consumption. The use of thecontrol valve 60 or voice coil valve described above allows the coil,spool and sliding tube to be driven in either direction withoutrequiring a spring for return motion, which in turn reduces the powerconsumption of the control valve, which can result in longer operationalperiods between charging and/or smaller power supplies (e.g. batteries),resulting in greater freedom and less weight for the amputee. Inaddition, the use of the control valve 60 or voice coil valve describedabove allows the hydraulic system 40 and prosthetic knee 10 to have afaster response time to provide a more natural gait to the amputeeand/or to provide a more natural transition between sitting andstanding, and/or climbing stairs.

The control valve 60 or voice coil valve can be carried by and attachedto the cylinder 54 or another frame member of the hydraulic actuator ordamper 50. As described above, the housing or cartridge 100 of thecontrol valve 60 or voice coil valve can have a fitting 104 and/or anouter tube 126 that engages and attaches to the housing, and thus thecontrol valve, to the upper cap 72 of the cylinder. In addition, thecontrol valve 60 or voice coil valve, or housing 100 thereof, can belocated behind the cylinder 54. Furthermore, the control valve 60 orvoice coil valve can be oriented with a path of travel of the coil 144,spool 114 and sliding tube 116 parallel with a path of travel of thepiston 58. The position and orientation of the control valve 60 or voicecoil valve can create a more compact and smaller profile for theprosthetic knee, and thus greater freedom, comfort and natural movementfor the amputee, because the control valve 60 or voice coil valve can belarger than prior art solenoid valves.

In addition, the control valve 60 or voice coil valve, and thus thehydraulic valve 80, has a pair of different regions of substantiallylinear control. A first region provides a region of control during slowextension and/or retraction (or compression) of the hydraulic actuatoror damper, between 1.5 to 2.5 inches per second and is by definition thesmaller of the two regions; and a second region provides for a region ofcontrol during fast extension and/or retraction (or compression) of thehydraulic actuator or damper, between 6 to 8 inches per second. Asdescribed above, one or more orifices 110 in the inner tube 122 can beselectively aligned with one or more openings 118 of the sliding tube116 to achieve the pair of control regions with different flow rates. Inone aspect, the orifice(s) 110 can have a longitudinally varying widthwith a discrete change in width from a proximal end to a distal endalong a longitudinal length of the orifice. For example, the orifice canhave a larger or wider proximal end, and a smaller or narrower distalend, as shown in FIGS. 5b and 6b . Thus, the orifice 110 can have twodiscrete widths formed by two orifices sharing a common boundary that isopen between the two orifices. As shown in FIGS. 5b and 6b , theorifice(s) 110 can have a larger proximal rectilinear (square orrectangular) shape and a smaller distal rectilinear shape, which share acommon boundary and that are open to one another. In another aspect, alarger number of orifices(s) and opening(s) can be aligned ormisaligned. In another aspect, the shape, size, number and/or locationof the orifice(s) and/or opening(s) can be configured to provide the twolinear regions.

Referring to FIGS. 5a-6b , the operation of the hydraulic system 40, thehydraulic actuator or damper 50, the control valve 60 or voice coilvalve, the hydraulic valve 80 and electric actuator 90 is demonstrated.FIGS. 5a and b show the hydraulic system in compression and the controlvalve more “closed” or more restricted to have a lower flow rate and agreater resistance, which can correspond to knee flexion (or the lowermember 18 pivoting towards the upper member 14). Thus, the knee can flexor compress more slowly or with greater resistance. It is noted,however, that the knee can flex or compress more rapidly and with lesserresistance (i.e. with the control valve more “open” or less restricted)depending on the gait cycle. FIGS. 6a and b show the hydraulic system inextension and the control valve more “open” or less restricted to have agreater flow rate and a lesser resistance, which can correspond to kneeextension (or the lower member 18 pivoting away the upper member 14).Thus, the knee can extend more rapidly or with lesser resistance. It isnoted, however, that the knee can extend more slowly and with greaterresistance (i.e. with the control valve more “closed” or morerestricted) depending on the gait cycle.

Referring to FIGS. 5a and b , the hydraulic actuator or damper 50 iscompressed; the piston 58 is compressed into the cylinder 54; hydraulicfluid is displaced by the piston out of the (lower) chamber or portionof the cylinder, through a portion of the channel in the lower cap 70,through the tube 74 to the upper cap 72 or manifold, and into the distalportion 66 b of the channel 66 in the upper cap 72 or manifold. Thehydraulic fluid is displaced into the control valve 60 or voice coilvalve through and into the inner tube 122, and through and into thesliding tube 116 or spool 114, and to the opening(s) 118 in the slidingtube or spool. As shown in FIGS. 5a and b , the opening(s) 118 of thesliding tube 116 or spool 114 is misaligned with the orifice(s) 110 inthe inner tube 122, or aligned with the smaller or narrower distal endor portion thereof; creating a smaller cross-sectional area throughwhich the fluid can flow, and thus increasing resistance to the flow anddecreasing the flow rate so that the piston 58 moves with greaterdifficulty and more slowly in the cylinder 54, and the lower member 18moves with greater difficulty and more slowly in compression. Thehydraulic fluid is displaced through the opening(s) 118 of the slidingtube 116 or spool 114, and the orifice(s) 110 in the inner tube 122. Thehydraulic fluid is displaced through the outer tube 126, out of thecontrol valve 60 or voice coil valve, into the proximal portion 66 a ofthe channel 66 in the upper cap 72 or manifold, and into the (upper)chamber or portion of the cylinder. (Because of the piston rod 62 in theupper chamber of the cylinder, the opposite sides of the chamber changevolume unequally. Thus, excess fluid can be diverted into an overflowreservoir 154.) Also as shown in FIGS. 5a and b , the control valve 60or voice coil valve, or actuator 90, has been moved in a first or distaldirection under an applied current (and polarity) to selectivelyposition the spool 114 or sliding tube 116, and thus selectivelyposition or misalign the orifice(s) 110 and opening(s) 118. As discussedabove, the control valve can be operated to move in a proximal directionto align the orifice(s) and the opening(s) to create a largercross-sectional area, and thus reduce resistance to flow and increasethe flow rate so that the lower member moves faster in extension, orwhen the knee is coming forward during the gait cycle.

Referring to FIGS. 6a and b , the hydraulic actuator or damper 50 isextended; the piston 58 is extended or withdrawn away from the cylinder54; hydraulic fluid is displaced by the piston out of the (upper)chamber or portion of the cylinder, through a portion of the channel inthe upper cap 72, and into a proximal portion 66 a of the channel 66 inthe upper cap 72 or manifold. The hydraulic fluid is displaced into thecontrol valve 60 or voice coil valve through and into the outer tube126, and to the orifice(s) 110 in the inner tube 122. As shown in FIGS.6a and b , the opening(s) 118 of the sliding tube 116 or spool 114 isaligned with the orifice(s) 110 in the inner tube 122, or the larger orwider proximal end or portion thereof (or in this case the entireorifice); creating a larger cross-sectional area through which the fluidcan flow, and thus reducing resistance to the flow and increasing theflow rate so that the piston 58 moves easier and more quickly in thecylinder 54, and the lower member moves easier and more quickly inextension. The hydraulic fluid is displaced through the opening(s) 118of the sliding tube 116 or spool 114, and the orifice(s) 110 in theinner tube 122. The hydraulic fluid is displaced out of the controlvalve 60 or voice coil valve through and out of the sliding tube 116 orspool 114, and through and out of the inner tube 122 to the distalportion 66 b of the channel 66 in the upper cap 72 or manifold. Thehydraulic fluid is displaced through the tube 74 to the lower cap 70,and into the (lower) chamber or portion of the cylinder. (Again, becauseof the piston rod 62 in the upper chamber of the cylinder, the oppositesides of the chamber change volume unequally. Thus, the deficient fluidcan be withdrawn from the overflow reservoir.) Also as shown in FIGS. 6aand b , the control valve 60 or voice control valve, or actuator 90, hasbeen moved in a second or proximal direction under an applied current(and opposite polarity) to selectively position the spool 114 or slidingtube 116, and thus selectively position or align (or misalign) theorifice(s) 110 and opening(s) 118. As discussed above, the control valvecan be operated to move in a distal direction to misalign the orifice(s)and the opening(s) to create a smaller cross-sectional area, and thusincrease resistance to flow and reduce the flow rate so that the lowermember moves slower in compression, or knee flexion.

Thus, as described above, the control valve or voice coil valve providesselectively adjustable greater resistance and less flow rate tocompression. In another aspect, the operation as described above can bereversed, with the control valve or voice coil valve providing greaterresistance and less flow rate to extension.

In another aspect, an opposite rod can be formed on the piston on theopposite side of the piston rod so that the opposite chambers changevolume equally. For example, see FIGS. 22 and 23.

As stated above, the prosthetic knee 10 can include a power supply (suchas batteries 158) and control electronics (such as a circuit board witha microprocessor, not shown and as understood by those of skill in theart). The actuator 90 can be electrically coupled to the controlelectronics and power supply to control and drive the actuator, and thusthe operation of the prosthetic knee. In addition, the prosthetic kneecan have pressure sensors 162 operatively coupled to the flow channel 66on opposite sides of the orifice(s) to sense pressure on opposite sidesof the piston. The sensors can be attached to the upper cap 72 ormanifold, and operatively coupled to the proximal and distal portions 66a and 66 b of the flow channel. The sensors can be electrically coupledto the control electronics.

The prosthetic device 10 and/or the control valve 60 or voice coil valvecan also have a non-powered state in case power is lost, with a pressurecontrol valve that is opened by a pressure imbalance, thus allowinghydraulic fluid flow between the opposite sides of the chamber. The flowcontrol valve can allow different flow rates and different resistance inopposite directions through a separate set of the hydraulic flowchannels in the non-powered state. The pressure control valve can allowa higher flow rate and a lower resistance during extension of thehydraulic actuator or damper, or the pair of prosthetic members. Inaddition, the pressure control valve can allow a lower flow rate and ahigher resistance during retraction of the hydraulic actuator or damper,or the pair of prosthetic members. The pressure control valve caninclude at least one safety port 180 through a spool, such as the spoolof the control valve. The coil can have an unpowered positioned, eitherbiased or unbiased, in which the safety port of the spool or slidingtube is aligned with the orifice or other safety port in the inner tube.The operation as described above can be reversed.

Furthermore, as shown in FIG. 7, the prosthetic knee 10, or hydraulicsystem thereof, can have an externally adjustable bypass valve 188 thatis manually operated and fluidly coupled to a bypass channel between theopposite sides of the cylinder to allow the members to pivot.

Referring to FIGS. 8-10, another prosthetic knee 310 is shown inaccordance with an embodiment of the present invention, which is similarin most respects to that described above, and which description ishereby incorporated herein by reference. As discussed above, thecoupling of the hydraulic actuator or damper 350 can be reversed withrespect to that described above, with the cylinder 354 coupled to theupper member 314, and the piston rod 362 of the piston 358 coupled tothe lower member 318. In addition, the control valve 360 or voice coilvalve can be carried by and directly coupled to the hydraulic actuatoror damper 350. The control valve can have a housing that is integrallyformed from at the same time with the cylinder (and even the capopposite the piston) as a single monolithic housing to reduce theoverall size of the hydraulic system 340 and accommodate the larger sizeof the voice coil valve (with respect to a solenoid valve). Thus, thecontrol valve 360 or voice coil valve can be carried by and attached tothe cylinder 354 or another frame member of the hydraulic actuator ordamper 350. Furthermore, the control valve (or path of travel of thespool) can be aligned with the hydraulic actuator or damper (or the pathof travel of the piston); which can help reduce the size or profile ofthe hydraulic system.

Referring to FIGS. 11-14 c, another prosthetic knee 410 is shown inaccordance with an embodiment of the present invention, which is similarin most respects to that described above, and which description ishereby incorporated herein by reference, but with a control valve orvoice coil valve disposed in the piston. As discussed above, thecoupling of the hydraulic actuator or damper 450 can be reversed withrespect to that described above in FIGS. 1-7, with the cylinder 454coupled to the upper member 414, and the piston rod 462 of the piston458 coupled to the lower member 418.

In addition, the control valve 460 or voice coil valve can be carried byand disposed in the piston 458. The control valve 460 or voice coilvalve is movable with the piston 458 inside the hydraulic cylinder 454or chamber, and the hydraulic channel 466 extends through the piston458.

The control valve 460 or voice coil valve, and the hydraulic valve 480and the actuator 490 thereof, can be disposed in a housing or cartridge500 attached to the piston 458. The hydraulic channel 466 can be formedby a central opening in a face of the piston on one side, and an annularopening on the other side of the piston between the housing and thepiston.

The hydraulic valve 480 of the control valve 460 is operatively coupledin the hydraulic flow path or channel 466, and includes at least oneorifice 110 and a spool 114 movable with respect to one another toselectively resist flow of the hydraulic fluid through the orifice. Thespool 114 can be selectively positioned with respect to the orifice(s)110 to selectively increase and decrease a cross-sectional area throughwhich the hydraulic fluid can flow. The spool 114 can be sliding tube116 defining, and can have a distal end or at least one distal opening118 that is selectively positionable with respect to the orifice 110.The distal opening 118 can be formed in a sidewall of the sliding tube116, or the open end thereof. The orifice(s) 110 can be formed in aninner tube 122 circumscribing the sliding tube 116 or spool 114. Thus,the spool 114 or sliding tube 116 can be selectively positioned by theactuator to selectively position the orifice(s) 110 and opening(s) 118with respect to one another, and selectively increase and decrease across-sectional area through which the hydraulic fluid can flow. Inanother aspect, a distal end of the sliding tube or spool can bepositioned with respect to the orifice. The sliding tube 116 can slidewithin the inner tube 122. In another aspect, the spool or sliding tubecan circumscribe the inner tube (as opposed to the inner tubecircumscribing the spool or sliding tube). The inner tube 122 can berigidly affixed to the housing 500, and can extend out of the housingand into the piston 458, and through the piston to the opposite sidethereof.

As stated above, the electric actuator 490 is coupled to the hydraulicvalve 480 to move the orifice(s) 110 and the spool 114 or sliding tube116 with respect to one another. The actuator 490 includes a permanentmagnet 140 and a coil 144 movable with respect to one another, anddisposed in the housing 500 movable with the piston 458 in the cylinder454. The magnet 140 can have an outer wall or cup with an annular shapeor a cup shape with an inner post forming an annular space between theouter wall and the inner post. The magnet 140 has or creates a magneticfield. The coil 144 can have an annular wall or cup sized to fit in theannular space of the magnet. The coil 144 can include wires wrapped orcoiled around the wall or cup. Thus, the coil 144 can be movablypositioned in the magnetic field of the magnet 140. A current can beapplied to the coil 144 to move the coil with respect to the magnet 140.As described above, the current applied to the coil 144 in the magneticfield of the magnet 140 produces a force that is directly proportionalto the electric current applied. In addition, the coil 144, and thus thecontrol valve 60, has a substantially linear time and force response.Furthermore, the coil 144, and thus the spool 114 or sliding tube 116,is bi-directionally driven by the current, or polarity thereof. Theelectric current applied to the coil 144 causes the coil, and thus thespool 114 or sliding tube 116, to move in either a first direction or asecond direction based on a polarity of the electric current. Thus, thecoil 144, spool 144 and sliding tube 116 are reciprocally positionablewith current polarity induced, bi-directional movement, by selectivelychanging the polarity of the electric current applied to the electricactuator 90 or coil. Thus, the spool 114 and sliding tube 116 can beselectively positioned and bi-directionally driven in back and forthdirections, so that the hydraulic valve 80 selectively varies theresistance, or effective surface area or size of the opening between theorifice(s) 110 and opening(s) 118, of the hydraulic valve 80, via theposition of the spool 114 or sliding tube 116 with respect to the innertube 122, to the flow of hydraulic fluid through the flow channel ororifice(s) 110 and opening(s) 118 thereof. The control valve 60 oractuator 90 can have a rapid response rate, greater than 100 cycles persecond, and a low power consumption, less than 1.8 Watts (i.e. or 150mAmps @ 12V). Furthermore, the control valve 60, and the coil 144thereof, can be selectively and proportionally positionable,proportional to an amount of the electric current applied to coil or thecontrol valve. Thus, a selective and variable amount of electric currentapplied to the coil or control valve selectively and proportionallyvaries the resistance of the control valve, or the hydraulic valve 80thereof, to the flow of hydraulic fluid through the flow channel.

The control valve 460 can be characterized as a voice coil valve, andthe actuator 490 can be characterized as a voice coil. Therefore, theprosthetic knee 410 and the hydraulic system 440 and the piston 458thereof can utilize a voice coil valve. As noted above, the controlvalve 460 or voice coil valve described above provides bi-directionalpositioning, proportional control, rapid response and/or low powerconsumption. The use of the control valve 460 or voice coil valvedescribed above allows the coil, spool and sliding tube to be driven ineither direction without requiring a spring for return motion, which inturn reduces the power consumption of the control valve, which canresult in longer operational periods between charging and/or smallerpower supplies (e.g. batteries), resulting in greater freedom and lessweight for the amputee. In addition, the use of the control valve 460 orvoice coil valve described above allows the hydraulic system 440 andprosthetic knee 410 to have a faster response time to provide a morenatural gait to the amputee and/or to provide a more natural transitionbetween sitting and standing, and/or climbing stairs. Disposing thecontrol valve 460 or voice coil valve in the piston 458 also allows fora more compact size or profile, but at the expense of cylinder height orlength.

While the above control valve 460 or voice coil valve has been describedas having a coil movable with respect to a permanent magnet, it iscontemplated that such a configuration can be reversed, with the magnetcoupled to the spool or sliding tube, and movable with respect to thecoil.

The control valve 460 or voice coil valve can also have a non-poweredstate in which case power is lost, and the control valve is opened by apressure imbalance, thus allowing hydraulic fluid flow between theopposite sides of the chamber. The control valve can allow differentflow rates and different resistance in opposite directions through thehydraulic flow channel in the non-powered state. The control valve canallow a higher flow rate and a lower resistance during extension of thehydraulic actuator or damper, or the pair of prosthetic members. Inaddition, the control valve can allow a lower flow rate and a higherresistance during retraction the hydraulic actuator or damper, or thepair of prosthetic members. The control valve can include at least onesafety port 580 through a spool of the control valve. The coil can havean unpowered positioned, either biased or unbiased, in which the safetyport of the spool or sliding tube is aligned with the orifice or othersafety port in the inner tube.

In addition, the control valve 460 or voice coil valve, and thus thehydraulic valve 480, has a pair of different, substantially linearcontrol regions, as described above.

Referring to FIGS. 13a-14c , the operation of the hydraulic system 440,the hydraulic actuator or damper 450, the control valve 460 or voicecoil valve, the hydraulic valve 480 and electric actuator 490 isdemonstrated with the valve disposed within the piston. FIGS. 13a and bshow the hydraulic system in compression and the control valve more“closed” or more restricted to have a lower flow rate and a greaterresistance, which can correspond to knee flexion (or the lower member418 pivoting towards the upper member 414). Thus, the knee can flex orcompress more slowly or with greater resistance. It is noted, however,that the knee can flex or compress more rapidly and with lesserresistance (i.e. with the control valve more “open” or less restricted)depending on the gait cycle. FIGS. 14a and b show the hydraulic systemin extension and the control valve more “open” or less restricted tohave a greater flow rate and a lesser resistance, which can correspondto knee extension (or the lower member 418 pivoting away the uppermember 414). Thus, the knee can extend more rapidly or with lesserresistance. It is noted, however, that the knee can extend more slowlyand with greater resistance (i.e. with the control valve more “closed”or more restricted) depending on the gait cycle.

Referring to FIGS. 13a and b , the hydraulic actuator or damper 450 iscompressed; the piston 458 is compressed into the cylinder 454;hydraulic fluid is displaced by the piston out of the (lower) chamber orportion of the cylinder (note that the control valve is inverted in FIG.13a ), through the central opening in the piston and into the inner tube122. The hydraulic fluid is displaced into the control valve 460 orvoice coil valve through and into the inner tube 122, and through andinto the sliding tube 116 or spool 114, and to the opening(s) 118 in thesliding tube or spool. As shown in FIGS. 13a and b , the opening(s) 118of the sliding tube 116 or spool 114 is misaligned with the orifice(s)110 in the inner tube 122, or aligned with the smaller or narrowerdistal end or portion thereof; creating a smaller cross-sectional areathrough which the fluid can flow, and thus increasing resistance to theflow and decreasing the flow rate so that the piston moves under greaterresistance and more slowly in the cylinder, and the lower member moveswith difficulty and more slowly in flexion. The hydraulic fluid isdisplaced through the opening(s) 118 of the sliding tube 116 or spool114, and the orifice(s) 110 in the inner tube 122. The hydraulic fluidis displaced through the channel 466 in the piston, and into the (upper)chamber or portion of the cylinder (again, note the control valve isinverted). (Because of the piston rod 462 in the upper chamber of thecylinder, the opposite sides of the chamber change volume unequally.Thus, excess fluid can be diverted into an overflow reservoir 554. Inanother aspect, an opposite rod can be formed on the piston on theopposite side of the piston rod so that the opposite chambers changevolume equally.) Also as shown in FIGS. 13a and b , the control valve460 or voice coil valve, or actuator 490, has been moved in a first ordistal direction under an applied current (and polarity) to selectivelyposition the spool or sliding tube, and thus selectively position oralign the orifice(s) and opening(s).

Referring to FIGS. 14a and b , the hydraulic actuator or damper 450 isextended; the piston 458 is extended or withdrawn away from the cylinder454; hydraulic fluid is displaced by the piston out of the (upper)chamber or portion of the cylinder (again, note that the control valveis inverted), and through the channel 466 in the piston. The hydraulicfluid is displaced into the control valve 460 or voice coil valvethrough the annular opening, and to the orifice(s) 110 in the inner tube122. As shown in FIGS. 14a and b , the opening(s) 118 of the slidingtube 116 or spool 114 is aligned with the orifice(s) 110 in the innertube 122, or the larger or wider proximal end or portion thereof (or inthis case the entire orifice); creating a larger cross-sectional areathrough which the fluid can flow, and thus reducing resistance to theflow and increasing the flow rate so that the piston moves easier andmore quickly in the cylinder, and the lower member moves easier and morequickly in flexion. The hydraulic fluid is displaced through theopening(s) 118 of the sliding tube 116 or spool 114, and the orifice(s)110 in the inner tube 122. The hydraulic fluid is displaced out of thecontrol valve 460 or voice coil valve through and out of the slidingtube 116 or spool 114, through and out of the inner tube 122 to thecentral opening in the piston, and into the (lower) chamber or portionof the cylinder (again note that the control valve is inverted).

Again, because of the piston rod 462 in the upper chamber of thecylinder, the opposite sides of the chamber change volume unequally.Thus, the deficient fluid can be withdrawn from the overflow reservoir.

In another aspect, the piston rod can continue through the piston andexit the opposite side of the working chamber so that the sum of thevolume in the opposite chambers doesn't change.

As described above, the linear piston damper system (or piston andcylinder) can utilize tightly toleranced components which eliminate theneed for elastomeric seals to separate the sides of the hydraulicchamber. By using a “metal-on-metal” fit between the piston andcylinder, the seal drag (or stiction) which would be transferred to theamputee as a jarring or disjointed feeling, can be entirely removed fromthe system, or greatly reduced. The precision that can be required toform a hydraulic working chamber capable of locking without weeping canrequire a gap between the acting surfaces of the piston and cylinder onthe order of 0.005 mm (0.0002 in) (i.e. between 0.05 mm and 0.0005 mm).Furthermore, the surface finish that can required to facilitate smoothactuation on both surfaces of the piston and cylinder can be between0.20 to 0.41 μm (8 to 16 μin) Ra finish.

Also as shown in FIGS. 14a and b , the control valve 460 or voice coilcontrol valve, or actuator 490, has been moved in a second or proximaldirection under an applied current (and opposite polarity) toselectively position the spool or sliding tube, and thus selectivelyposition or align (or misalign) the orifice(s) and opening(s).

The control valve 460 or voice coil valve can also have a non-poweredstate in which case power is lost, and the control valve is opened by apressure imbalance, thus allowing hydraulic fluid flow between theopposite sides of the chamber. The control valve can allow differentflow rates and different resistance in opposite directions through thehydraulic flow channel in the non-powered state. The control valve canallow a higher flow rate and a lower resistance during extension of thehydraulic actuator or damper, or the pair of prosthetic members. In oneaspect, the control valve can have a check valve or plurality of checkvalves 566 with a larger bore oriented and configured to allow thehigher flow rate and the lower resistance during extension, as shown inFIG. 14c . In addition, the check valve can allow a lower flow rate anda higher resistance during retraction the hydraulic actuator or damper,or the pair of prosthetic members. In one aspect, the control valve canhave a check valve 568 with a smaller bore oriented and configured toallow the lower flow rate and the higher resistance during compression,as shown in FIG. 13c , with flexion being the opposite. The controlvalve can include at least one safety port 580 through a spool of thecontrol valve. The coil can have an unpowered positioned, either biasedor unbiased, in which the safety port of the spool or sliding tube isaligned with the orifice or other safety port in the inner tube.

As also shown in FIGS. 13a and 14a , the piston rod 462 can have ahollow 570 with electrical wires 574 electrically coupled to the coil inthe piston and extending through the hollow of the piston rod to exitthe hydraulic chamber.

While the above control valve 460 or voice coil valve has been describedas being disposed in and carried by the piston, it is contemplated thatsuch a configuration can be reversed, with the control valve or voicecoil valve disposed in and carried by the cylinder.

Disposing the control valve or voice coil valve in the hydraulicactuator or damper, with the path of travel of the spool colinear oraligned with the path of travel of the piston, can lengthen thehydraulic actuator or damper, but also reduce the lateral size orprofile of the hydraulic system to increase comfort and use to theamputee.

Referring to FIGS. 15-20, another prosthetic knee 610 is shown inaccordance with an embodiment of the present invention, which is similarin most respects to that described above, and which description ishereby incorporated herein by reference, but with a rotary vane typehydraulic actuator or damper 650. The hydraulic system 640 and hydraulicactuator or damper 650 can be coupled between the upper and lowermembers 614 and 618 that are pivotally coupled together at a primarypivot, rotor or axle 622.

The hydraulic actuator or damper 650 includes a hydraulic chamber,namely a rotary chamber 654 forming an arc with an apex and an oppositeouter arcuate concave wall 656 that is rigidly coupled to the lowermember 618, and pivotally coupled to the upper member 614. The chamber654 can be formed by or can include a central block 700 forming thehydraulic chamber with the arc formed therein and open on lateral sides,and a pair of plates 704 closing the open lateral sides of the centralblock. The plates 704 can form all or a portion of the lower member 618or a shank link or a shin frame. Thus, the number of parts is reduced.

The hydraulic actuator or damper 660 also includes a piston or rotaryvane 658 pivotally disposed in the rotary chamber 656, and rigidlycoupled to the rotor 622 and the upper member 614. The rotor 622 extendsthrough the rotary chamber 656 at the apex thereof, and is pivotal withrespect to the rotary chamber. The rotary vane 658 has a proximal endattached to the rotor 622, and an opposite distal end with an outerarcuate convex wall matching the wall 656 of the rotary chamber. Thevane 658 divides the chamber 656 into opposite sides.

Hydraulic fluid can fill the chamber, and can be displaced from one sideof the chamber to the other as the vane moves therein. A hydraulic flowchannel 666 is fluidly coupled between the opposite sides of the chamberto allow the hydraulic fluid to move or displace between the oppositesides of the chamber as the vane moves therein. The hydraulic flowchannel 666 is coupled to both sides of the rotary chamber 654 atopenings 708 in the outer arcuate concave wall 656 on opposite ends ofthe arc. The rotary vane, in this embodiment, 658 can have indentations712 in opposite sides of the vane extending into the outer arcuateconvex wall to accommodate the openings 708 of the hydraulic flowchannel 608.

A manifold 772 can be attached to the central block 700. The manifold772 can have at least a portion of the hydraulic flow channel 666 formedtherein. Within the manifold 772, the hydraulic channel 666 can have aproximal portion 666 a and a distal portion 666 b (the proximal anddistal positions being relative to the control valve 660. A bore 676 canbe formed in the manifold 672, and can extend through the proximalportion 666 a of the hydraulic channel 666 to the distal portion 666 b.As described above, the control valve 660 or voice coil valve can becoupled to the manifold 772 at the bore 676. The control valve or voicecoil valve can be disposed in the lower member 618 to create a smallerprofile for user comfort.

The above central block 700 and rotary vane 658 can be made with closetolerance so that a seal is not necessary between the block and vane.The rotary vane damper system (or vane and rotary chamber) can utilizetightly toleranced components which eliminate the need for elastomericseals to separate the sides of the hydraulic chamber. By using a“metal-on-metal” fit between the piston and cylinder, the seal drag (orstiction) which would be transferred to the amputee as a jarring ordisjointed feeling, can be entirely removed from the system, or greatlyreduced. The precision that can be required to form a hydraulic workingchamber capable of locking without weeping can require a gap between theacting surfaces of the vane and rotary chamber on the order of 0.005 mm(0.0002 in). Furthermore, the surface finish that can required tofacilitate smooth actuation on both surfaces of the vane and rotarychamber can be between 0.20 to 0.41 μm (8 to 16 μin) Ra finish.Referring to FIG. 20, another central block 700 and rotary vane 658 b isshown with a seal 790 carried by the vane between the vane and theblock.

One advantage of the prosthetic knee with the rotary vane configurationdescribed above is that there are fewer working and/or moving parts, andthus lower cost and lower weight. In addition, there is no need for anoverflow reservoir or variable volume section for the hydraulic fluidbecause the chamber has a fixed volume or the opposite sides of thechamber sum to a constant regardless of the angle of the vane. Torque isgenerated about the rotation axis by controlling the flow of fluid fromone side of the vane to the other. Furthermore, a linear torquecapability is independent of angle, i.e. there is no “fall-off” due tolinkage ratio, as there would be with a linear piston damper system.

Referring to FIG. 21, another hydraulic system 840 for a prosthetic kneeis shown in accordance with an embodiment of the present invention,which is similar in most respects to those described above, and whichdescription is hereby incorporated herein by reference, but with a twinwall cylinder piston type hydraulic actuator or damper 850 to provide acompact cylindrical dimension. The actuator or damper 850 can include adouble walled cylinder 854 with a piston 858 disposed in an innercylinder or tube 855. An outer cylinder or tube 857 can circumscribe theinner cylinder 855 and form a hydraulic flow channel 866 therebetween.Thus, the cylinders 855 and 857 and the flow channel 866 can beconcentric. The inner and outer cylinders can define a pair ofconcentric cylinders.

The outer cylinder or tube 857 can be disposed between opposite caps 870and 872. One cap 870 can be formed integrally with the inner cylinder ortube 855 with the inner cylinder or tube 855 extending from the cap 870into the outer cylinder or tube 857. An opposite cap 872 can close boththe opposite ends of the inner and outer cylinders 855 and 857 oppositethe first cap. The control valve or voice coil valve 860 can be carriedby and disposed in the opposite cap 872. Thus, both the piston and thecontrol valve are disposed in the outer cylinder 857, while the pistonis disposed in the inner cylinder 855. The control valve or voice coilvalve can be aligned with, parallel with, and/or have concentric axiswith the piston.

An orifice 810 can be formed in the cap 872 and the control valve orvoice coil valve 860 can include a spool 814 movable with respect to thecap 872 and the orifice 810. The spool 814 can have an opening 818selectively movable and alignable with the orifice 810, as describedabove. The control valve actuation and the piston damper share a commoncenterline.

The piston 858 can include a reservoir therein to form a fluidcompensator. The hydraulic fluid moves from one side of the piston tothe other by flowing around the circumference of the area traveled bythe piston.

As described above, an opposite rod can be formed on the piston on theopposite side of the piston rod so that the opposite chambers changevolume equally. Referring to FIGS. 22 and 23, another hydraulic system940 for a prosthetic knee is shown in accordance with an embodiment ofthe present invention, which is similar in most respects to thosedescribed above, and which description is hereby incorporated herein byreference, but with a through rod piston cylinder type hydraulicactuator or damper 950 which will not require a variable volume tooperate as equal amounts of shaft or rod enter and leave the cylinder atthe same time.

The hydraulic actuator or damper 950 includes a hydraulic chamber,namely a hydraulic cylinder 954, pivotally coupled to the lower member,and a piston 958 with a piston rod 962 pivotally coupled to the uppermember. The piston 958 divides the chamber or cylinder 954 into oppositesides. The cylinder 954 can be formed by a cylinder disposed betweenopposite caps 970 and 72, one of which can be a lower cap 970 that canbe pivotally coupled to the lower member, and the other of which can bean upper cap 72 that has an aperture to slidably receive the piston rod962 that can be pivotally coupled to the upper member. The piston rodextends from the piston and out one side of the cylinder or chamber. Inaddition, the hydraulic actuator or damper 950 and/or piston 958includes an opposite or through rod 963 extending from an opposite sideof the piston from the piston rod 962. The opposite rod extends out anopposite side of the cylinder or chamber. The lower cap 970 has anaperture to slidably receive the opposite rod 963. The opposite rod 963can have the same diameter, and thus the same volume, as the piston rod962. Thus, as the piston 958 slides or displaces through the cylinder954, the same amount of hydraulic fluid is displaced in both directions,reducing or eliminating the need for an overflow reservoir. Thus, thechamber or cylinder has a constant volume as the piston and rods movetherein.

The piston rod 962 and the opposite rod 963 can be coupled together,such as by screwing a male threaded end of one into a female threadedbore in the end of the other. The piston 958 can be sandwiched orclamped between the two rods. Thus, one or both rods can pass through anaperture in the piston. An annular channel (radially facing) can beformed in one of the rods and between the rods to receive the pistontherein. In addition, an annular bumper and/or stop 959 can be carriedby the rods (such as sandwiched therebetween along with the piston)adjacent the piston to abut to one of the caps (such as cap 72) at theend of the travel of the piston. The bumper and/or stop 959 can includean annular rigid tray with an annular channel (facing axially) toreceive an annular bumper member formed of a flexible and resilientmaterial, and/or an elastic material. Thus, the bumper and/or stop canprovide a cushion or soft feel to extension of the hydraulic system andextension of the knee.

The through rod piston cylinder type hydraulic actuator or damper 950without a variable volume has a cylinder or working chamber with aconstant volume that can create the same forces in both directions andin both tension and compression, with no need to displace the variablevolume before creating force on one side. If high force is needed on theside of the piston or cylinder or working chamber which would haveencompasses the variable volume in a cylinder without the through rod,and if high spring rate is needed in the variable volume to balance theforce of moving this variable volume out of the way, then potentiallycavitating of the oil can occur because the metering orifice is closedand fluid is not flowing. With through rod piston cylinder typehydraulic actuator or damper 950, however, a high spring rate variablevolume, which would increase energy consumption on an above knee amputeeas he/she initiates swing flexion, is not needed, and lower total energyconsumption is a net result.

In addition, the cylinder 954 can be pivotally coupled to the lowermember (or upper member) by the cap 970. The opposite sides of the cap970 can be pivotally coupled to the lower member on lateral sides of thecylinder, cap or opposite rod 963 with the opposite rod 963 extendingand/or displacing through the pivot axis to form a compact hydraulicsystem, as shown in FIG. 23.

While the forgoing examples are illustrative of the principles of thepresent invention in one or more particular applications, it will beapparent to those of ordinary skill in the art that numerousmodifications in form, usage and details of implementation can be madewithout the exercise of inventive faculty, and without departing fromthe principles and concepts of the invention. Accordingly, it is notintended that the invention be limited, except as by the claims setforth below.

1-32. (canceled)
 33. A prosthetic device, comprising: a) a pair ofprosthetic members movably coupled together to allow movement of thepair of prosthetic members with respect to one another; b) a hydraulicactuator or damper including hydraulic fluid in a hydraulic chambercoupled to one of the pair of prosthetic members, and a hydraulic pistonmovably disposed in the hydraulic chamber and coupled to another of thepair of prosthetic members; c) a hydraulic flow channel fluidly coupledbetween opposite sides of the chamber to allow hydraulic fluid to movebetween the opposite sides of the chamber as the hydraulic piston movestherein; and d) a voice coil valve coupled to the hydraulic flow channelto vary resistance to flow of hydraulic fluid through the flow channel,wherein the voice coil valve in a non-powered state allows a hydraulicfluid to move between the opposite sides of the chamber through aseparate hydraulic flow channel.
 34. The device of claim 33, wherein thevoice coil valve comprises a safety port.
 35. The device of claim 34,wherein the voice coil valve comprises an orifice, a spool, and thesafety port is through the spool.
 36. The device of claim 35, whereinthe safety port is aligned with the orifice in the non-powered state.37. The device of claim 36, wherein the safety port is biased to bealigned with the orifice in the non-powered state.
 38. The device ofclaim 33, wherein the voice control valve allows different flow ratesand different resistance in opposite directions through the separatehydraulic flow channel in the non-powered state.
 39. The device of claim33, wherein the voice coil valve is reciprocally positionable withcurrent polarity induced, bi-directional movement, by selectivelychanging a polarity of an electric current applied to the voice coilvalve, such that the voice coil valve is selectively positioned andbi-directionally driven in back and forth directions.
 40. The device ofclaim 39, wherein the voice coil valve is selectively positionableproportional to an amount of the electric current applied to the voicecoil valve, such that a selective and variable amount of electriccurrent applied to the voice coil valve selectively and proportionallyvaries the resistance of the voice coil valve to the flow of hydraulicfluid through the flow channel.
 41. The device of claim 33, wherein thevoice coil valve includes a permanent magnet and a coil movable withrespect to one another; and wherein an electric current applied to thecoil causes a spool to move in either a first direction or a seconddirection based on a polarity of the electric current.
 42. The device ofclaim 41, wherein a force generated by the coil is directly proportionalto the electric current applied.
 43. The device of claim 33, wherein thevoice coil valve has a substantially linear time and force response. 44.The device of claim 33, wherein the hydraulic flow channel comprises anorifice and a spool movable with respect to one another to selectivelyresist flow of the hydraulic fluid through the orifice.
 45. The deviceof claim 44, wherein the voice coil valve comprises an electric actuatorcoupled to the hydraulic valve to move the orifice and the spool withrespect to one another, including a permanent magnet and a coil movablewith respect to one another, and reciprocally positionable with currentpolarity induced, bi-directional movement, by selectively changing thepolarity of the electric current applied to the electric actuator, suchthat the spool is selectively positioned and bi-directionally driven inback and forth directions, such that the hydraulic valve variesresistance to the flow of hydraulic fluid through the flow channel. 46.The device of claim 33, wherein the voice coil valve has a coil and aspool with a path of travel parallel with a path of travel of thepiston.
 47. The device of claim 33, wherein the voice coil valve isdisposed in and carried by the piston, and movable with the pistoninside the hydraulic chamber, and the hydraulic channel extends throughthe piston.